In this proposal, we will investigate the computations for cue combination underlying auditory spatial sensitivity in the nucleus of the brachium of the inferior colliculus (BIN). We will characterize the receptive fields for both location and frequenc by presenting sound stimuli while simultaneously recording extracellular responses from neurons in the BIN. In addition, we will characterize and model multi-cue interaction underlying these receptive fields by measuring responses to sound stimuli with random spectral shapes. The results of this study will elucidate the neural mechanisms underlying the integration of sound localization cues necessary for the formation of objects in the ascending auditory system. An unsolved problem in auditory neural prostheses is producing an adequate sense of the spatial location of stimuli. This information is important for spatial unmasking in multi-talker environments as well as for localizing sounds. An understanding of how auditory spatial fields are constructed in the BIN should be useful in determining which sound localization cues need to be provided and in what form. Finally, the results of this work are also a prerequisite for planning an experimental investigation of the deficits in the sound localization representation in hearing impairment.